On Wednesday, May gave permission to extend the ban on marching to the City of London, which includes the Square Mile and its surrounding areas, following a request from police chiefs. Assistant commissioner Frank Armstrong of the City of London police said: "This is not a decision we take lightly, but is, we believe, an appropriate response to prevent a displaced march or demonstration resulting in serious public disorder within the City of London."

Police said the original ban was issued following information that the march could cause "serious public disorder, violence and damage". They added: "Tactically we believe this is the best option to prevent this."

Announcing the ban, Chief Superintendent Julia Pendry warned EDL supporters to stay away, adding: "We do not want people coming into the areas to attend these events."

The order does not prevent the EDL from holding a static protest and its website says there will be a "static demonstration" in Tower Hamlets on Saturday, although there are no details. Some anti-racist campaigners have said they will hold a counter demonstration.

The EDL march had been vehemently opposed by community leaders, among them the two local MPs and the east London borough's mayor, as well as Muslim and Jewish groups. Fears that it could spark violence were exacerbated after the riots this month.

The blanket ban on marches will last for 30 days and has been criticised by some as a counter-productive move that will prevent a range of other legitimate protests.

Members of the group deny any official contact with Breivik and insist their organisation is peaceful, non-racist and opposed to extremism. A Guardian investigation into the EDL found repeated racism and threats of violence among supporters.

A spokesman for the Met said: "We are currently in discussions with organisers regarding their intentions."